This phase I study of CPT-11 in refractory solid tumor patients with hepatic dysfunction aims to determine the maximum tolerated dose, to ascertain the pharmacodynamics and pharmacokinetics of irinotecan and its active metabolite, to evaluate qualitative and quantitative toxicities, and to assess the antitumor activity of the agent. Irinotecan is hepatically metabolized and all patients enrolled on this study will have some degree of hepatic dysfunction. This study will permit a greater understanding of which elements of liver dysfunction are related to the metabolism of and toxicity from irinotecan.